ExpertGlossary terms starting with L

1,745 terms

LDEF Long Duration Exposure Facility (NASA).
LDH One of a group of enzymes found in the blood and other body tissues, and involved in energy production in cells.
ldifde A command-line tool for importing and exporting directory contents to and from Active Directory / ADAM, such as schema definitions and directory objects…
LDL (or low-density lipoprotein ) A combined protein and fatlike substance. Rich in cholesterol, it tends to stick to the walls in the arteries. Sometimes called "bad cholesterol."
LDM Abbreviation for limited distance modem.
LDP ldp.exe is a graphical user interface (GUI) tool for general administration of a Lightweight Directory Access Protocol (LDAP) directory service.
LDR Low Data Rate.
LDS Lightning Detection System
LDT Local Daylight Time.
LE Lethality Enhancer (PAC-3).
Le Grande The best hand in Baccarat, a 9. See Natural
Leach To remove components from the soil by the action of water trickling through.
Leachate A liquid that results from water collecting contaminants as it trickles through wastes, agricultural pesticides or fertilizers.
Leachates Liquids percolated through waste piles. Leachate can include various minerals, organic matter, or other contaminants and can contaminate surface water or…
Leaching Removal of soluble material from soil or other permeable material by the passage of water through it.
Leaching field (leaching cesspool) A lined or partially lined underground pit into which raw household water (sewage) is discharged and from which the liquid seeps into the surrounding soil.
Leaching requirement Quantity of irrigation water required for transporting salts through the soil profile to maintain a favorable salt balance in the root zone for plant…
Lead A gray-white metal that is listed as a criteria air pollutant. Health effects from exposure to lead include brain and kidney damage and learning…
Lead Acid Battery An electrochemical battery that uses lead and lead oxide for electrodes and sulfuric acid for the electrolyte.
Lead Agency The agency within a Part B consortium that is responsible for contract administration; also called a fiscal agent (an incorporated consortium sometimes…
Lead Barges The head or first barge(s) of tow.
Lead Component/ Service The DoD Component designated by SECDEF to be responsible for management of a system acquisition involving two or more DoD Components in a joint program.
lead compound A chemical that has demonstrated promising biological activity in preliminary assays.
Lead lap The lap that the race leader is currently on.
Lead Line Small line, manila or sash cord, to measure depth of water.
Lead time Time available for Decision Makers to determine if conditions at a dam and reservoir, or in the basin, warrant declaration of a specific emergency…
Lead underwriter When a company wants to raise capital by selling securities to investors, it partners with an investment bank, known as the lead underwriter.
Leade A horizontal or vertical cylinder, usually made of metal, which carries water from the gutter to the ground.
Leaded window A window composed of small panes, usually diamond-shaped or rectangular, held in place by narrow strips of cast lead.
Leader The streamer which initiates the first phase of each stroke of a lightning discharge.
leader peptide See: signal sequence.
leader sequence A variable length sequence of nucleotides at the 5' end of an mRNA molecule that precedes the AUG initiation codon where translation begins and is not…
Leader Spot In solar-terrestrial terms, in a magnetically bipolar or multipolar sunspot group, the western part precedes and the main spot in that part is called the…
Leadership in Energy and Environmental Design (LEED) Green Building Rating System is a nationally accepted benchmark for the design, construction, and operation of high performance green buildings.
leadhead, lead-head A term for a jig where lead is molder to the hook shaft.
Leading Edge In reference to a wind energy conversion system, the area of a turbine blade surface that first comes into contact with the wind.
Leading question A question that suggests the answer desired of the witness. A party generally may not ask one's own witness leading questions.
leading strand The strand of DNA that is synthesized continuously during replication.
Leading/Ledding The amount of space between lines of printed text.
LEAF Law Enforcement Access Field.
leaf blade The usually flattened portion of the leaf.
leaf bud cutting A cutting that includes a short section of stem with attached leaf.
leaf margin The edge of a leaf.
leaf primordium A lateral outgrowth from the apical meristem, which will become a leaf when fully developed and expanded.
leaf roll A symptom of some virus diseases, characterized by curling of the leaves. Can also occur as a response to water stress.
leaf scar Mark left on a stem after leaf abscission.
leaflet Expanded leaf-like part of a compound leaf.
Leak Uncontrolled loss of water by flow through a hole or crack.
Leakage Free flow loss of water through a hole or crack.
Leakage (Max) The maximum allowable threat objects passing through a BMD system expressed as a percentage of the design-to threat.
Leaking Electricity Related to stand-by power, leaking electricity is the power needed for electrical equipment to remain ready for use while in a dormant mode or operation.
leaky bucket counter A counter that is incremented by one each time an event occurs and is decremented by a fixed value periodically. [T1.218-1991]
leaky mode In an optical fiber, a mode having a field that decays monotonically for a finite distance in the transverse direction but becomes oscillatory everywhere…
leaky mutant A mutant in which the gene product still retains some biological activity.
leaky ray In an optical fiber, a ray for which geometric optics would predict total internal reflection at the boundary between the core and the cladding, but which…
LEAP Lightweight Exoatmospheric Projectile.
leap second An occasional adjustment of one second, added to, or subtracted from, Coordinated Universal Time (UTC) to bring it into approximate synchronism with UT1…
Leapfrog Development Development that occurs beyond the limits of existing development and creates areas of vacant land between areas of developed land.
Leasable minerals Federal minerals such as coal, oil shale, oil, gas, phosphate, potash, sodium, tar sands, geothermal resources, potassium, asphaltic materials, and all…
LEASAT Leased Satellite.
Lease A contract transferring the use of property or occupancy of land, space, structures, or equipment in consideration of a payment (e.g., rent).
Lease of power privilege Contractual right given to a non-Federal entity to utilize, consistent with project purposes, water power head and storage from Reclamation projects for…
Lease Purchase (Lease Option) Assists low to moderate income homebuyers in purchasing a home by allowing them to lease a home with an option to buy; the rent payment is made up of the…
Lease-Purchase Option An option sometimes used by sellers to rent a property to a consumer, who has the option to buy the home within a specified period of time.
leased circuit Dedicated common-carrier facilities and channel equipment used by a network to furnish exclusive private line service to a specific user or group of users.
Least cost planning (integrated resource planning) A method of power planning that recognizes load uncertainty, embodies an emphasis on risk management, and reviews all…
Least Privilege This principle requires that each subject in a system be granted the most restrictive set of privileges (or lowest clearance) needed for the performance…
least significant bit In a binary code, the bit or bit position that is assigned to, or represents, the smallest quantity or increment that can be represented by the code.
least-cost path The path, among possibly many, between two points which has the lowest traversal cost, where cost is a function of time, distance, or other user-defined…
least-time principle Synonym Fermat's principle.
leave to sit Permission for a committee to meet during the proceedings of the parent chamber.
Leaving line Lines that are left on barges when dropped off to fleet operation.
LEC Abbreviation for local exchange carrier.
lectin A complex molecule that has both protein and sugars. Lectins are able to bind to the outside of a cell and cause biochemical changes in it.
LED (1) Low Endoatmospheric Defense. (2) Light Emitting Diode.
LED therapy (...THAYR-uh-pee) Treatment with drugs that become active and may kill cancer cells when exposed to light.
ledge A severe drop-off. Commonly found in Arizona's deep canyon lakes, such as Canyon Lake, Lake Powell, Lake Mead, Blue Ridge Reservoir and Chevelon Lake.
LEDI Low Endoatmospheric Defense Interceptor.
LEDS (1) Low Endoatmospheric Defense System. (2) Link Eleven Display System (USN term).
Lee The side or part that is sheltered or turned away from the wind, such as with a mountain.
Lee Wave The wavelike effect, characterized by severe updrafts and downdrafts, that occurs in the lee of a mountain range when rapidly flowing air is lifted up the…
LEED "Plus" Created by the Massachusetts Sustainable Design Roundtable to address shortcomings with standard LEED certification these standards apply to construction…
LEEP A technique that uses electric current passed through a thin wire loop to remove abnormal tissue.
Lees Ferry The popular 16-mile stretch of tail-water fishery along the Colorado River tucked between the Glen Canyon Dam and the Grand Canyon in northern Arizona.
Leeside Low Extratropical cyclones that form on the downwind (lee) side of a mountain chain.
Leeward The side away from the wind. Compare windward.
leflunomide An anticancer drug that works by inhibiting a cancer cell growth factor. Also called SU101.
Left Abutment See abutment.
Left Bank The left descending bank of a river. It is marked by red buoys, white or red lights and red reflectors.
Left Exit Region Used interchangably with Left Front Quadrant; the area downstream from and to the left of an upper-level jet max (as would be viewed looking along the…
Left Front Quadrant Used interchangably with Left Exit Region; the area downstream from and to the left of an upper-level jet max (as would be viewed looking along the…
Left Mover A thunderstorm which moves to the left relative to the steering winds, and to other nearby thunderstorms; often the northern part of a splitting storm.
Left or right designation In the context of dams and river channels, the designation of left or right is made with the observer looking in the downstream direction.
left shift A "bit shift" that multiplies the number by some power of 2.
left shift operator The left shift operator (<<) is a bit manipulation operator. It moves the bits in its left operand zero or more places to the left, according to the value…
left-hand (anti-clockwise) polarized wave An elliptically or circularly polarized wave, in which the electric field vector, observed in the fixed plane, normal to the direction of propagation…
Left-lateral fault See Fault, left-lateral
left-right topology The topological data structure ARC/INFO uses to represent contiguity between polygons. Left-right supports analysis functions such as adjacency.
leftmost longest The preference of the "regular expression" engine to match the leftmost occurrence of a "pattern", then given a position at which a match will occur, the…
Lefty A developmental factor that helps determine right-left asymmetry in vertebrates.